1. Field of the Invention
This invention relates to lubricant compositions and, in one of its aspects, relates more particularly to lubricant compositions, such as lubricating oils and greases which normally exhibit wearing effects on machinery with which they may come into contact.
2. Description of the Prior Art
Prior to the present invention, polypropylene glycols have been employed as anti-wear agents in lubricant compositions, such as lubricating oils and greases, in a wide variety of automotive and metal working applications. Their utility, however, in lubricant compositions is restricted because of poor compatability with lubricants, such as solvent refined paraffinic oils. It is therefore highly desirable to enhance the solubility of these polypropylene glycols in the lubricant compositions employed for various industrial applications.
In U.S. Pat. No. 3,124,531, lubricants for use in rolling of aluminum sheets and foil are described. Lubricants used in such operations must be volatile enough to evaporate during the metal annealing process and leave no residue or stain. This patent teaches producing such lubricants from light mineral oils having a viscosity of from about 30 to about 60 SUS at 100.degree. F. A fatty alcohol of the formula R--OH where R is a straight paraffinic chain of from 10 to 20 carbon atoms and polypropylene glycol are added to the light mineral oil to improve the lubricity,. This disclosure is distinguished from the compositions of the present invention in the viscosity of the lubricant employed. Additionally, sulfur, which is a necessary component of the compositions of the instant invention, must be excluded from the patentees composition due to its staining tendencies.
In U.S. Pat. No. 3,919,093, lubricant compositions which contain (1) an alkene oxide polymer, prepared by the reaction of from 1 to 30 moles of an alkylene oxide with from 70 to 99 moles of an alcohol, amine, amide, organic acid, phenol or mercaptan and (2) sulfur are disclosed.
Neither of these references disclose the novel composition of this invention.